Improvement in piston-packings



UNITED STATES J. RANDOLPH ABBE, OF FROVIDENCE, RHODE ISLAND.

Specification forming part of Letters Patent No. 42,999, dated June 7, 1864.

T0 all, whom it may concern:

' Beit known that I, J. RANDOLPH ABBE, of the city and county of Providence and State ot' Rhode Island, have invented a new and useful Improvement in Piston-Packings; and I do hereby declare that the followingis a full, clear, and exact descriptoxi thereof, which will enable others skilled in the art to make and use the same, reference being had to the ac companyiug drawiugsyfirming part of this specification, in wh'ch- Figure l is a central longitudinal section of the cylinder and piston ot' a steam engine. Fig. 2 is a face View ot' one ot' the cylinderheads. Fig. 3 is a view of the interior of the piston as exposed to view by the removal of the ftllower.

Similar letters of reference indicate corresponding parts.

This invention consists in a novel and very effective manner of setting out or adjusting the packing of a piston, whereby the necessity for removing the follower or any portion of the piston or of` the cylinder-head for that purpose is obviated.

A represents the head of the piston, G C the packing-rings, and B the follower. 'lhe lacking rings may be constructed and fitted in any well-known manner, and the follower tenured to the head by bolts a a iu the usual way.

E E are steel or brass springs applied within the packing-rings to press them outward. These springs have holes in their centers for the reception of screws b b, which are fitted to move longitudinally in holts bored for their reception into the body of the piston in a (i rection radial to the center thereof, and the said springs are iirmly secured to the said screws by means of clamping-nuts c d inside and outside. The inner ends of the said :crews are supported againstthe oblique surfaces of the wedge shaped heads e', of a corresponding number of screws, e e, which are arianged parallel with the axis of the piston. l hese heads e are so fitted into mortises in the nistonhead A as to be prevented from turning, and the screws e e are iitted with nutsff, the exteriors of which are toothed like cogwheels, as shown at h hin Fig. l, to gear with an internally-toothed ring, F, which is fitted to turn freely in a concentric circular cavity, g, formed in the piston-head between it and the follower B. The nuts are prevented from having any other than a rotary movement by being turned to a circular form and itted to bearings provided for them in the interior of the follower, and are confined endwise between the head and follower. Their teeth are received in the cavity g, before mentioned, in which they are free to turn.

G is a spur-gear arranged within the cavity g and gearing' with the toothed ring F. This gear is fast on one end of a spindle, i, which is iitted to a bearing provided for it in the head A, and the other end of which is flush with the face of the head and made with a square, i', around which the said bearing is counter'sunk, as shown at j in Fig. l, for the reception of a key to be applied to the square for turning the spindle.

By applying a suitable key to the square i of the spindle t' and turning it the gear G is made to turn the toothed ring F, which is made to turn all the toothed nuts fj'simulta` neously and equally, and thereby to produce an equal longitudinal movement of all the screws e e, thereby causing the wedges e either to force outward the screws p p and springs E E, and so make them produce a greater outward pressure on the packing, or else to permit the said screws and springs to move inward and rcduce such pressure according tothe d-irection in which the key is turned.

In order to permit the piston-packing to be adjusted without removing either of the cylinder-heads D D, a hole, u, is provided in the head I), which is opposite the exposed square end ofthe spindle l, and the said hole is iitted with a screw-plug, H, or with other means of closing it up steam-tight. When it is desired to adjust the packing, the piston is run up as near as possible to the cylinder-head D', the plug H, or its equivalent, is removed, and the key inserted thrt ugh the hole n and applied to the spindle i.

In order to enable it to be seen how far the spindle is turned by the key, there is provided on the exteiior of the cylinder-head, around the key-hole i1, a cicular graduated scale, s,

(shown in Fig. 2,) and there is a. mark made ou ring.r F, toothed gear (Land spindle the Whole t'le key to serve as an index in connection applied to operate substantially-'as and for the Wth this scale. purpose herein specified.

I Claim as new and desire to secure by Lettcrs Pateut J. RANDOLPH ABBE.

I he combination of the screws b Z1, or their -Witnessesz equivalents, the screws e e, having Wedge- WILLIAM J. MITCHELL,

shaped heads7 the toothed nuts fj', toothed ORLAND WM. PRINCE. 

